Raymond E. Umbaugh founded Umbaugh Aircraft Corporation of Ocala, Florida in 1957. He build and sold several single-seat Bensen Gyrocopters before he started the design of a tandem two-seat gyrocopter in 1958. The first flight of the prototype Umbaugh 18 took place in August 1959, thereafter Fairchild Engine and Airplane Corporation was to develop and produce the model in quantity.
The all-metal prototype flew initially with one vertical tail, than a butterfly tail and finally with a tailplane with three vertical fins on top of it, the middle fin could turn. The engine powered a pusher airscrew with the three-blade rotor being pre-rotated for vertical take-off, also called "jump-start". The rotor and control systems were extremely simple having swashplate control for the blades, and as the rotor was not powered inflight no anti-torque system was necessary. Longitudinal and lateral control was affected by mechanically tilting the rotor plane.
During 1960 Fairchild produced five development airframes under the designation Flymobil. The gyrocopter received its Type Certificate in September 1961. The contract between Umbaugh and Fairchild planned the production of 10,000 U-18, however this was not to materialize. Umbaugh Aircraft Corporation ceased operations in 1962; in 1964 Air & Space Manufacturing Inc. of Muncie, Indiana was founded and took over series production.
Early 1965 the production certificate was issued for the Air & Space U-18A differing only in detail from the earlier Umbaugh 18, except that it was fitted with rotor blades made of wood, reinforced with glass fiber. By late 1965 over 100 were claimed to have been build but there have been reports that only between 65 and 75 were actually completed and delivered to customers. Air & Space ran into financial trouble and ceased operations after bankruptcy in 1966.
Umbaugh 18: Fairchild U-18 Flymobil: Air & Space U18-A:
Specifications (Avalon 680)
Max T/O weight:
Two-seat light gyroplane
One 180 hp Lycoming O-360-A1D four-cylinder horizontally-opposed engine
35 ft 0 in (10.67 m) in diameter
25 ft 0 in (7.62 m) fuselage only
ft 6 in (3.51 m)
962 sq.ft (89.37 sq.m)
1,800 lb (816 kg)
126 mph (203 km/h)
1,050 ft (320 m)/min
17,000 ft (5,181 m)
360 mls (579 km)